Infections Flashcards
CMV - IgM + - what % have infection?
25%
Can persist for months after primary infection, and recur with reactivation
Symptoms primary CMV
Usually asymptomatic
May have a viral illness
Risk factors for CMV acquisition
Child care workers (12% seroconversion/y)
parents with children in day are
CMV general population seroconversion
2%/y
Prenatal diagnostic testing
Amnio for CMV PCR
at least 6 weeks after primary infection
Sensitivity ~100% >21/40
USS low sensitivity and specificity `
USS features of CMV
Microcephaly Ascites Oligo/poly Abdominal/intracranial calcification hydrocephalus Hydrops IUGR Hepatomegaly
Prevention of CMV transmission
- No role of IVIG in prevention
Management of confirmed foetal CMV infection
- TOP, with the knowledge it is difficult to predict the severity of infection based on PCR and USS
- IVIG - better clinical outcomes for babies at 1 year in one non-randomised trial
CMV - risk of transmission with seroconversion
- risk of symptomatic CMV
- risk of sequelae
30%
- with transmission: (overall 10-20% risk long term squeal of congenitally infected child)
- 10% symptomatic > 50% sequelae
- 90% asymptomatic > 10% sequelae
Clinical signs of symptomatic CMV
- high early mortality
- microphaly
- seizures
- chorioretinitis
- developmental delay
- sensorineural hearing loss
Newborn Ix for CMV
- Examination
- Serology
- Urine/salive PCR
> if + then opthal and radiological (USS and MRI)
> Rx w oral valganciclovir
Practices for reducing infection with CMV
- Assume children <3y in your care have CMV
- Thoroughly wash hands with soap and water after touching child/toys/nappies/feeding/bathing etc
- Don’t share cups, plates, utensils, toothbrushes or food
- Do not kiss the child on or near the mouth
- Do not share a bed w the child
- Do not share towels or washcloths
Prevalence rubella
1/100 000 pregnancies
Symptom rubella infection
50% asymptomatic
Vague coryzal symptoms
Examthem: maculopapular, face>trunk, resolves face>trunk
+/- polyarthralgia
+/- tender lymphadenopathy
Forchemers spots (rose like) on soft palate
Diagnosis of rubella infection
4x increase in IgG titre (usually 2/52)
IgM +
Culture +
Amnio/CVS PCR
Diagnosis of neonatal congenital rubella infection
IF IgM + at birth > retest 1/12
Infant Rubella IgG higher for longer than expected (maternal IgG lasts ~6/52)
Chance of foetal infection across gestations (Rubella)
T1 80%
T2 30%
T3 100%
Congenital rubella infection vs congenital rubella syndrome
Infection: - MC - SB - Birth defects - Asymptomatic - IUGR Syndrome: = constellation of birth defects - hearing impairment - congenital heart defect - cataracts/glaucoma - pigmentary retinopathy
Rx rubella in pregnancy
Prevention - vaccine prepreg
Supportive care
Rx of complications e.g. steroids for thrombocytopenia
Manage the foetus: discuss TOP (esp <16/40), no direct in utero Rx
Manifestations of congenital infection EARLY
- Hearing loss 60%
- Heart defects 45% (PDA, pulmonary stenosis)
- Microcephaly 25%
- Cataracts 25%
- IUGR 25%
- hepatosplenomegaly/jaundice/purpura/pneumonitis
- meningoencephalitis
Manifestations of congenital rubella infection LATE
- Hearing loss
- Intellectual disability
- DM
- Thyroid dysfn
- Progressive pan-encephalitis
- Immune defects
Neonatal follow up after rubella infection
- Clinical attendants at birth should be rubella immune
- IX: IgM, Urine PCR, culture urine and throat swab (can take weeks)
- Opthal, cardiac and hearing assessments at birth
- Regular clinical assessment
- May be infectious for 1y of life
Risk of congenital defects by gestational age (Rubella)
T1 ~85%
13-16/40 ~35%
>16/40 - rare
HSV seroprevalence
HSV 1= 60%
HSV 2 = 20%
Risk of HSV transmission if in genital tract in labour (recurrent)
HSV 1 15%
HSV 2 <0.01%
Overall 1-3%
HSV - difference between primary and non-primary first infection?
Primary - HSV 1 and 2 serology negative
Non-primary = seropositive for other serotype
Risk of HSV transmission for primary HSV?
If maternal seroconversion well before efelivery e.g. prior to 30-24/40, then as for recurrent.
No maternal seroconversion - 25-50%
Can you get in utero HSV infection?
Yes
Rare
<1%
Can cause abortion, PTB and IUGR
Scalp clip with known genital HSV?
No
Increases transmission RR 6.8!
Indications for CS with HSV?
- New HSV diagnosed in labour
- Primary HSV diagnosed late in pregnancy
- After maternal discussion with recurrent lesions in labour
Exposed neonate (primary or systemic infection), or neonate with symptoms (skin lesions, seizures, sepsis, low plt, deranged LFTs, DIC, resp distress, corneal ulcers)
Ix: LP, LFTs, FBE, HSV PCR blood, surface swabs
Immediately commence IV Aciclovir20mg/kg TDS
Recurrent genital HSV lesins in labour
Leave membranes intact as long as possible
Avoid FBS
Avoid instrumental delivery
Expedite delivery
Listeria - organism
Bacteria Listeria monocytogenes Aerobic, facultative anaerobe Motile B-haemolytic Gram + rod Tumbling motility by light microscopy Grows well at refrigeration temperatures Predilection for the placenta and CNS
Listeria - Symptoms
Febrile flu like illness Malaise / HA / Backache Abdo pain Pharyngitis Conjunctivitis Diarrhoea ARDS Asymptomatic (1/3)
Ix Listeria
Blood culture
Genital tract gram stain and culture
Rx Listeria
Amoxycillin/Ampicillin 2g Q6H IV x14/7
Gent x 14/7
(Pen allergy Trimethoprim/Sulphamethoxazole - not in T1, w folate)
Incidence Listeria
0.3/100 000
Foetal mortality w maternal Listeriosis T2/3?
~50%
Asymptomatic individuals with consumption of food implicated in outbreak of Listeria - Rx?
Yes (suggested)
Amoxyl 2-3g/d
Incubation Listeria
Broad
1-67 days
Preg average 6/52
Neonatal symptoms of Listeriosis
Granulomatosis infantiseptica - placenta, cord or post pharyngeal granulomas, small skin granulomas, pustular skin rash
MEc liquor < 34/40
Pneumonitis
Purulent conjunctivitis
Neonatal Ix and Rx
Culture: placenta, swabs, blood cultures, urine and CSF
CXR
FBE
Rx: Amoxycillin and Gent (14-21 days dependent on culture results)
Perinatal listeriosis
Early onset <7/7
- often fulminant disease
- mort 20-60%
Late onset 7/7-6/52
- usually meningitis or sepsis
- mort 10-20%